Not applicable.
Not applicable.
This invention relates to unloading systems for automatically emptying containers of their contents, and more particularly, to a retaining arm assembly for use in such systems.
In automated unloading systems, a container is first constrained within a holding fixture. The fixture is pivotable about an axis so to rotate the container from an initial, upright position to a substantially inverted position. At this inverted position, the contents of the container spill out of the container into another receptacle, for example, or onto a conveyor. The fixture is then rotated back to its original position in which the container is returned to its upright position. The container is then released from the fixture so a new container can be set in place. During this unloading operation, it is desirable that the container not slide out of, or fall through, the fixture.
One problem of current unloading systems is their inability to accommodate a variety of different size and shaped containers. In the U.S. Postal System, for examples, containers can be very tall wire or metal frame containers, relatively short containers made of a molded plastic, or cloth hampers. It is extremely advantageous that an unloading system be able to unload each type of container, automatically, and without having to modify the system each time a different size container is to be unloaded.
For purposes of flexibility, the unloading system should be able to accommodate containers of various sizes and be able to hold the container, regardless of is size, firmly in place throughout the unloading or dumping cycle. Otherwise, if the container slides or falls out of the fixture, the contents of the container may not be completely emptied, and secondary operations will be required, adding to the time of the unloading operation and its cost. In this latter regard, it is important that the container be held in place so that it cannot inadvertently fall off the fixture and cause injury to people. A restraint, such as described herein, holds containers of various sizes in the fixture so these types of problems do not occur.
Among the several objects of the present invention may be noted the provision of a retaining arm assembly for use in a container unloading system. The assembly utilizes a plurality of mechanical arms arranged on opposite sides of an unloading fixture into which containers of various sizes can be loaded for emptying of their contents. The arms on each side of the container are commonly mounted on a pivot post. When a container is placed in the fixture, the arms are pivoted into a position where they contact the container. Throughout the dumping cycle, an arm on each post, above the top of the container, is in a position which blocks movement of the container in the direction by which it might otherwise slide out of, or fall off the fixture. After unloading is completed and the fixture is returned to its initial position, the arms are pivoted away from the container and it is removed from the fixture. It is an advantage of the invention that the arms are spaced along the length of the pivot post so that as containers of different sizes are set in the fixture, one or more arms on each side of the fixture is moved into a container blocking position. The assembly insures that the containers are held in place throughout the unloading operation so that the contents of containers are properly dumped, no spillage occurs, and the container cannot fall out of the fixture. The retaining arm assembly provides a relatively low cost, easy to install and repair solution to unloading operations in which a variety of different size containers must be accommodated without having to alter the unloader installation as different size containers are brought in for unloading. Other objects and features will be in part apparent and in part pointed out hereinafter.